The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 02, 1992
Filed:
Sep. 05, 1990
Applicant:
Inventors:
Assignee:
Kubota Corporation, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B60K / ; B60K / ;
U.S. Cl.
CPC ...
180242 ; 91473 ; 91488 ; 180305 ; 180307 ;
Abstract
A propelling apparatus for a vehicle switchable between a four wheel drive mode and a two wheel drive mode. The apparatus comprises a hydraulic pump for driving hydraulic motors associated with front wheels and rear wheels, respectively. A shutoff valve is provided on oil lines extending between the hydraulic pump and one of the hydraulic motors, e.g. the motor associated with the front wheels. The shutoff valve is operable to establish the two wheel drive mode for driving only the rear wheels. A pumping preventive device prevents the hydraulic motor associated with the front wheels from effecting pumping action due to power transmitted from the front wheels when the shutoff valve is operated.